Uterine-specific SIRT1 deficiency confers premature uterine aging and impairs invasion and spacing of blastocyst, and stromal cell decidualization, in mice

Polystyrene microplastics disturb maternal glucose homeostasis and induce adverse pregnancy outcomes

Pregnant women are a special group that is sensitive to adverse external stimuli, causing metabolic abnormalities and adverse pregnancy outcomes. Microplastics (MPs), an environmental pollutant widely used in various fields, can induce a variety of toxic responses in mammals. Recent studies verified an association between MPs and metabolic disorders. Our research built a gestational mouse model in which polystyrene microplastics (PS-MPs) of 1 μm size were consumed at concentrations of 0.1, 1, and 10 mg/L during pregnancy. Results indicated that PS-MPs induced placental malfunction and fetal growth retardation. Significant glucose disorders, decreased liver function, hepatic inflammation, and oxidative stress were also observed after PS-MPs exposure. The hepatic SIRT1/IRS1/PI3K pathway was inhibited in the 10 mg/L PS-MPs exposure group. Our study found that PS-MPs activated inflammatory response and oxidative stress by increasing hepatic lipopolysaccharide (LPS) that inhibited the hepatic SIRT1/IRS1/PI3K pathway, ultimately leading to insulin resistance, glucose metabolism disorders, and adverse pregnancy outcomes. This study provides a basis for preventing environment-related gestational diabetes and concomitant adverse pregnancy outcomes.

Transcriptome analysis of adenomyosis eutopic endometrium reveals molecular mechanisms involved in adenomyosis-related implantation failure and pregnancy disorders

BACKGROUND

Women with adenomyosis are characterized by having defective decidualization, impaired endometrial receptivity and/or embryo-maternal communication, and implantation failure. However, the molecular mechanisms underlying adenomyosis-related infertility remain unknown, mainly because of the restricted accessibility and the difficult preservation of endometrial tissue in vitro. We have recently shown that adenomyosis patient-derived endometrial organoids, maintain disease-specific features while differentiated into mid-secretory and gestational endometrial phase, overcoming these research barriers and providing a robust platform to study adenomyosis pathogenesis and the associated molecular dysregulation related to implantation and pregnancy disorders. For this reason, we aim to characterize the dysregulated mechanisms in the mid-secretory and gestational endometrium of patients with adenomyosis by RNA-sequencing.

METHODS

Endometrial organoids were derived from endometrial biopsies collected in the proliferative phase of women with adenomyosis (ADENO) or healthy oocyte donors (CONTROL) (n = 15/group) and differentiated into mid-secretory (-SECorg) and gestational (-GESTorg) phases in vitro. Following RNA-sequencing, the significantly differentially expressed genes (DEGs) (FDR < 0.05) were identified and selected for subsequent functional enrichment analysis and QIAGEN Ingenuity Pathway Analysis (IPA). Statistical differences in gene expression were evaluated with the Student's t-test or Wilcoxon test.

RESULTS

We identified 1,430 DEGs in ADENO-SECorg and 1,999 DEGs in ADENO-GESTorg. In ADENO-SECorg, upregulated genes included OLFM1, FXYD5, and RUNX2, which are involved in impaired endometrial receptivity and implantation failure, while downregulated genes included RRM2, SOSTDC1, and CHAC2 implicated in recurrent implantation failure. In ADENO-GESTorg, upregulated CXCL14 and CYP24A1 and downregulated PGR were related to pregnancy loss. IPA predicted a significant inhibition of ID1 signaling, histamine degradation, and activation of HMGB1 and Senescence pathways, which are related to implantation failure. Alternatively, IPA predicted an inhibition of D-myo-inositol biosynthesis and VEGF signaling, and upregulation of Rho pathway, which are related to pregnancy loss and preeclampsia.

CONCLUSIONS

Identifying dysregulated molecular mechanisms in mid-secretory and gestational endometrium of adenomyosis women contributes to the understanding of adenomyosis-related implantation failure and/or pregnancy disorders revealing potential therapeutic targets. Following experimental validation of our transcriptomic and in silico findings, our differentiated adenomyosis patient-derived organoids have the potential to provide a reliable platform for drug discovery, development, and personalized drug screening for affected patients.

Reversing Uteropathies Including Cancer-Like Changes in Mice by Transplanting Mesenchymal Stromal Cells or XAR Treatment

Pluripotent, very small embryonic-like stem cells (VSELs) and tissue-committed 'progenitors' termed endometrial stem cells (EnSCs) are reported in mouse uterus. They express gonadal and gonadotropin hormone receptors and thus are vulnerable to early-life endocrine insults. Neonatal exposure of mouse pups to endocrine disruption cause stem/progenitor cells to undergo epigenetic changes, excessive self-renewal, and blocked differentiation that results in various uteropathies including non-receptive endometrium, hyperplasia, endometriosis, adenomyosis, and cancer-like changes in adult life. Present study investigated reversal of these uteropathies, by normalizing functions of VSELs and EnSCs. Two strategies were evaluated including (i) transplanting mesenchymal stromal cells (provide paracrine support) on D60 or (ii) oral administration of XAR (epigenetic regulator) daily from days 60-100 and effects were studied later in 100 days old mice. Results show normalization of stem/progenitor cells (Oct-4, Oct-4A, Sox-2, Nanog) and Wnt signalling (Wnt-4, β-catenin, Axin-2) specific transcripts. Flow cytometry results showed reduced numbers of 2-6 µm, LIN-CD45-SCA-1 + VSELs. Hyperplasia (Ki67) of epithelial (Pax-8, Foxa-2) and myometrial (α-Sma, Tgf-β) cells was reduced, adenogenesis (differentiation of glands) was restored, endometrial receptivity and differentiation (LIF, c-KIT, SOX-9, NUMB) and stromal cells niche (CD90, VIMENTIN, Pdgfra, Vimentin) were improved, cancer stem cells markers (OCT-4, CD166) were reduced while tumor suppressor genes (PTEN, P53) and epigenetic regulators (Ezh-2, Sirt-1) were increased. To conclude, normalizing VSELs/EnSCs to manage uteropathies provides a novel basis for initiating clinical studies. The study falls under the umbrella of United Nations Sustainable Development Goal 3 to ensure healthy lives and well-being for all of all ages.

Uterine Aging and Reproduction: Dealing with a Puzzle Biologic Topic

Uterine aging is the process of the senescence of uterine tissue, observed in all middle-aged mammals. Since the aging-related changes in the uterus are associated with infertility and poor pregnancy outcomes, with a lack of studies discussing uterine aging, authors reviewed uterine aging and its consequences on reproduction. MEDLINE, Scopus, and PubMed searches during the years 1990-2023 were performed using a combination of keywords and terms on such topics. According to the author's evaluation, articles were identified, selected, and included in this narrative review. The aging process has an unfavorable impact on the uterus of mammals. There are different and selected molecular pathways related to uterine aging in humans and animals. Uterine aging impairs the function of the uterine myometrium, neurofibers of the human uterus, and human endometrium. These biological pathways modulate oxidative stress, anti-inflammatory response, inflammation, mitochondrial function, DNA damage repair, etc. All these dysregulations have a role in poorer reproductive performance and pregnancy outcomes in older mammals. The most recent data suggest that uterine aging is accompanied by genetic, epigenetic, metabolic, and immunological changes. Uterine aging has a negative impact on the reproductive performance in mammalian species, but it could be potentially modulated by pharmacological agents, such as quercetin and dasatinib.

Steroid receptor coactivator-2 drives epithelial reprogramming that enables murine embryo implantation

Although we have shown that steroid receptor coactivator-2 (SRC-2), a member of the p160/SRC family of transcriptional coregulators, is essential for decidualization of both human and murine endometrial stromal cells, SRC-2's role in the earlier stages of the implantation process have not been adequately addressed. Using a conditional SRC-2 knockout mouse (SRC-2d/d ) in timed natural pregnancy studies, we show that endometrial SRC-2 is required for embryo attachment and adherence to the luminal epithelium. Implantation failure is associated with the persistent expression of Mucin 1 and E-cadherin on the apical surface and basolateral adherens junctions of the SRC-2d/d luminal epithelium, respectively. These findings indicate that the SRC-2d/d luminal epithelium fails to exhibit a plasma membrane transformation (PMT) state known to be required for the development of uterine receptivity. Transcriptomics demonstrated that the expression of genes involved in steroid hormone control of uterine receptivity were significantly disrupted in the SRC-2d/d endometrium as well as genes that control epithelial tight junctional biology and the emergence of the epithelial mesenchymal transition state, with the latter sharing similar biological properties with PMT. Collectively, these findings uncover a new role for endometrial SRC-2 in the induction of the luminal epithelial PMT state, which is a prerequisite for the development of uterine receptivity and early pregnancy establishment.

Flip a coin: cell senescence at the maternal-fetal interface†

During pregnancy, cell senescence at the maternal-fetal interface is required for maternal well-being, placental development, and fetal growth. However, recent reports have shown that aberrant cell senescence is associated with multiple pregnancy-associated abnormalities, such as preeclampsia, fetal growth restrictions, recurrent pregnancy loss, and preterm birth. Therefore, the role and impact of cell senescence during pregnancy requires further comprehension. In this review, we discuss the principal role of cell senescence at the maternal-fetal interface, emphasizing its "bright side" during decidualization, placentation, and parturition. In addition, we highlight the impact of its deregulation and how this "dark side" promotes pregnancy-associated abnormalities. Furthermore, we discuss novel and less invasive therapeutic practices associated with the modulation of cell senescence during pregnancy.

The NR2F2-HAND2 signaling axis regulates progesterone actions in the uterus at early pregnancy

Endometrial function is dependent on a tight crosstalk between the epithelial and stromal cells of the endometrium. This communication is critical to ensure a fertile uterus and relies on progesterone and estrogen signaling to prepare a receptive uterus for embryo implantation in early pregnancy. One of the key mediators of this crosstalk is the orphan nuclear receptor NR2F2, which regulates uterine epithelial receptivity and stromal cell differentiation. In order to determine the molecular mechanism regulated by NR2F2, RNAseq analysis was conducted on the uterus of PgrCre;Nr2f2f/f mice at Day 3.5 of pregnancy. This transcriptomic analysis demonstrated Nr2f2 ablation in Pgr-expressing cells leads to a reduction of Hand2 expression, increased levels of Hand2 downstream effectors Fgf1 and Fgf18, and a transcriptome manifesting suppressed progesterone signaling with an altered immune baseline. ChIPseq analysis conducted on the Day 3.5 pregnant mouse uterus for NR2F2 demonstrated the majority of NR2F2 occupies genomic regions that have H3K27ac and H3K4me1 histone modifications, including the loci of major uterine transcription regulators Hand2, Egr1, and Zbtb16. Furthermore, functional analysis of an NR2F2 occupying site that is conserved between human and mouse was capable to enhance endogenous HAND2 mRNA expression with the CRISPR activator in human endometrial stroma cells. These data establish the NR2F2 dependent regulation of Hand2 in the stroma and identify a cis-acting element for this action. In summary, our findings reveal a role of the NR2F2-HAND2 regulatory axis that determines the uterine transcriptomic pattern in preparation for the endometrial receptivity.

Histone modifications in embryo implantation and placentation: insights from mouse models

Embryo implantation and placentation play pivotal roles in pregnancy by facilitating crucial maternal-fetal interactions. These dynamic processes involve significant alterations in gene expression profiles within the endometrium and trophoblast lineages. Epigenetics regulatory mechanisms, such as DNA methylation, histone modification, chromatin remodeling, and microRNA expression, act as regulatory switches to modulate gene activity, and have been implicated in establishing a successful pregnancy. Exploring the alterations in these epigenetic modifications can provide valuable insights for the development of therapeutic strategies targeting complications related to pregnancy. However, our current understanding of these mechanisms during key gestational stages remains incomplete. This review focuses on recent advancements in the study of histone modifications during embryo implantation and placentation, while also highlighting future research directions in this field.

Uterine histotroph and conceptus development: III. Adrenomedullin stimulates proliferation, migration and adhesion of porcine trophectoderm cells via AKT-TSC2-MTOR cell signaling pathway

Adrenomedullin (ADM) as a highly conserved peptide hormone has been reported to increase significantly in the uterine lumen during the peri-implantation period of pregnancy in pigs, but its functional roles in growth and development of porcine conceptus (embryonic/fetus and its extra-embryonic membranes) as well as underlying mechanisms remain largely unknown. Therefore, we conducted in vitro experiments using our established porcine trophectoderm cell line (pTr2) isolated from Day-12 porcine conceptuses to test the hypothesis that porcine ADM stimulates cell proliferation, migration and adhesion via activation of mechanistic target of rapamycin (MTOR) cell signaling pathway in pTr2 cells. Porcine ADM at 10^-7 M stimulated (P < 0.05) pTr2 cell proliferation, migration and adhesion by 1.4-, 1.5- and 1.2-folds, respectively. These ADM-induced effects were abrogated (P < 0.05) by siRNA-mediated knockdown of ADM (siADM) and its shared receptor component calcitonin-receptor-like receptor (CALCRL; siCALCRL), as well as by rapamycin, the inhibitor of MTOR. Using siRNA-mediated knockdown of CALCRL coupled with Western blot analyses, ADM signaling transduction was determined in which ADM binds to CALCRL to increase phosphorylation of MTOR, its downstream effectors (4EBP1, P70S6K, and S6), and upstream regulators (AKT and TSC2). Collectively, these results suggest that porcine ADM in histotroph acts on its receptor component CALCRL to activate AKT-TSC2-MTOR, particularly MTORC1 signaling cascade, leading to elongation, migration and attachment of conceptuses.

Aclonifen could induce implantation failure during early embryonic development through apoptosis of porcine trophectoderm and uterine luminal epithelial cells

Aclonifen is a diphenyl-ether herbicide that is used to control the growth of weeds while growing crops such as corn and wheat. Although the biochemical effects of aclonifen are well characterized, including its ability to inhibit protoporphyrinogen oxidase and carotenoid synthesis, the toxicity of aclonifen in embryonic implantation and development during early pregnancy, has not been reported. Thus, in this study, we investigated the potential interference of aclonifen in embryonic implantation using porcine trophectoderm (pTr) and uterine luminal epithelial (pLE) cells isolated during implantation period of early pregnancy. Cell viability in both pTr and pLE cells significantly decreased in a dose-dependent manner following aclonifen treatment. Moreover, the proportion of cells in the sub-G1 phase of the cell cycle gradually increased upon treatment with increasing concentrations of aclonifen, which in turn led to an increase in the number of apoptotic cells, as determined by annexin V and propidium iodide staining. Aclonifen treatment caused mitochondrial dysfunction by increasing the depolarization of the mitochondrial membrane potential and the mitochondrial calcium concentration. Aclonifen inhibited cell mobility by suppressing the expression of implantation-related genes in pTr and pLE cells. To explore the underlying mechanism, we evaluated the phosphorylation of PI3K and MAPK signaling molecules. The phosphorylation of AKT, S6, JNK, and ERK1/2 were significantly increased by aclonifen. Collectively, our results suggest that aclonifen may interrupt implantation during early pregnancy by disrupting maternal-fetal interaction.